import java.util.Scanner;
class Isxiao extends Exception {
    public Isxiao(String message) {
        super(message);
    }
}
public class Haha {
    public static void main(String[] args) throws Isxiao {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        if (n < 0) {
            throw new Isxiao("此数小于0");
        } else {
            System.out.println(Math.pow(n, 2));

        }
    }
}